Wireless communication apparatus

ABSTRACT

A data unit that requires a receipt acknowledgement response in a plurality of transmitted data units is suitably selected.A wireless communication apparatus includes a control unit. The control unit controls transmission of receipt acknowledgement requests for a plurality of transmitted data units. Further, the receipt acknowledgement request whose transmission is controlled by the control unit is a receipt acknowledgement request including information, the information identifying a data unit that requires a receipt acknowledgement response in the plurality of transmitted data units and specifying the identified data unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/314,450, filed Dec. 31, 2018, now U.S. Pat. No. 10,841,067, which isbased on PCT filing PCT/JP2017/016373, filed Apr. 25, 2017, which claimspriority to JP 2016-134932, filed Jul. 7, 2016, the entire contents ofeach are incorporated herein by reference.

TECHNICAL FIELD

The present technology relates to a wireless communication apparatus.Specifically, the present technology relates to a wireless communicationapparatus that performs data exchange by using wireless communication.

BACKGROUND ART

In the past, frame aggregation to aggregate a plurality of data itemsinto one frame and transmit the frame has been performed in order toimprove the transmission efficiency in wireless communication. Forexample, a system to transmit/receive an A-MPDU (Aggregation MACProtocol Data Unit) in which a plurality of MAC (Media Access Control)frames are aggregated is used. In this system, a wireless communicationapparatus as a data transmission source transmits an A-MPDU, to performtransmission of a plurality of data items. Subsequently, in order todetermine a data item in the plurality of transmitted data items that isnot transmitted due to the occurrence of transmission errors, thewireless communication apparatus as a data transmission source furthertransmits a block ACK request frame. This block ACK request frame is aframe that requests delivery acknowledgement responses of all the dataitems previously transmitted. After reception of the block ACK requestframe, a wireless communication apparatus on the data reception sidereturns a block ACK frame in which a plurality of deliveryacknowledgements are aggregated. The wireless communication apparatus asthe data transmission source receives this block ACK frame, identifiesthe data item that causes a transmission error, and performsretransmission. In contrast to such a system, the following system isused: an A-MPDU with information of data that requests a deliveryacknowledgement response is transmitted to simplify deliveryacknowledgement processing in the wireless communication apparatus onthe reception side. For example, a system to transmit an A-MPDU isproposed, the A-MPDU including identification information showing thenecessity of a receipt acknowledgement for each data item (see, e.g.,Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Application Laid-open No.2005-252897

DISCLOSURE OF INVENTION Technical Problem

The conventional technology described above determines the necessity ofa delivery acknowledgement for each data item on the basis of thepriority of each data item, generates identification information, andadds the identification information to an A-MPDU for transmission. Thus,the delivery acknowledgement processing is omitted for data items havinga low priority in the wireless communication apparatus as a transmissiondestination of the A-MPDU. However, when a situation of a wirelesstransmission path or the like changes after the A-MPDU is transmitted, adata item that requires a delivery acknowledgement return cannot bechanged, and thus there arises a problem that convenience decreases.

The present technology has been created in view of such circumstancesand it is an object of the present technology to improve convenience bysuitably selecting a data item that requires a receipt acknowledgementresponse in a plurality of transmitted data items.

Solution to Problem

The present technology has been made in order to eliminate the problemdescribed above and a first aspect thereof is a wireless communicationapparatus including a control unit that controls transmission of areceipt acknowledgement request including information, the informationspecifying a data unit that requires a receipt acknowledgement responsein a plurality of transmitted data units. This provides such an actionthat a data unit that requires a receipt acknowledgement response in thetransmitted data is specified by the receipt acknowledgement request.

Further, in the first aspect, the control unit may generate theinformation according to a priority of each of the plurality oftransmitted data units. This provides such an action that a data unitthat requires a receipt acknowledgement response is identified accordingto the priority.

Further, in the first aspect, the control unit may generate theinformation on a basis of a reference priority, the reference prioritybeing a reference regarding necessity of the receipt acknowledgementresponse. This provides such an action that a data unit that requires areceipt acknowledgement response is identified on the basis of areference priority.

Further, in the first aspect, the control unit may change the referencepriority according to a situation of a wireless transmission path. Thisprovides such an action that a data unit that requires a receiptacknowledgement response is identified on the basis of a referencepriority that is changed according to a situation of the wirelesstransmission path.

Further, in the first aspect, the control unit may change the referencepriority according to an error rate of the wireless transmission path.This provides such an action that a data unit that requires a receiptacknowledgement response is identified on the basis of a referencepriority that is changed according to an error rate.

Further, in the first aspect, the control unit may change the referencepriority when the error rate of the wireless transmission path rises.This provides such an action that a reference priority is changed whenthe error rate rises.

Further, in the first aspect, the control unit may change the referencepriority according to a congestion degree of the wireless transmissionpath. This provides such an action that a data unit that requires areceipt acknowledgement response is identified on the basis of areference priority that is changed according to a congestion degree.

Further, in the first aspect, the control unit may change the referencepriority when the wireless transmission path is congested. This providessuch an action that a reference priority is changed with the rise of thecongestion degree.

Further, in the first aspect, the control unit may change the referencepriority according to a state of a transmission buffer that holds a dataunit to be transmitted. This provides such an action that a data unitthat requires a receipt acknowledgement response is identified on thebasis of a reference priority that is changed according to a state of atransmission buffer.

Further, in the first aspect, the control unit may change the referencepriority when data units held in the transmission buffer reach apredetermined amount. This provides such an action that a data unit thatrequires a receipt acknowledgement return is identified on the basis ofa reference priority that is changed according to the amount of dataunits held in the transmission buffer.

Further, in the first aspect, the control unit may generate theinformation according to a situation of a wireless transmission path.This provides such an action that a data unit that requires a receiptacknowledgement response is identified according to a situation of thewireless transmission path.

Further, in the first aspect, the control unit may generate, when thewireless transmission path is congested, the information in which thenumber of data units that require the receipt acknowledgement responsesis changed. This provides such an action that the number of data unitsthat require receipt acknowledgement responses is changed when thewireless transmission path is congested.

Further, in the first aspect, the control unit may generate theinformation according to a state of a transmission buffer that holdsdata units to be transmitted. This provides such an action that a dataunit that requires a receipt acknowledgement response is identifiedaccording to a state of the transmission buffer.

Further, in the first aspect, the control unit may generate, when thedata units held in the transmission buffer reach a predetermined amount,the information in which the number of data units that require thereceipt acknowledgement responses is changed. This provides such anaction that a data unit that requires a receipt acknowledgement responseis identified according to the amount of data units held in thetransmission buffer.

Further, in the first aspect, the control unit may set the data unitwhose timing of output to an application in a wireless communicationapparatus being a transmission destination of the plurality of dataunits has come as a data unit that does not require the receiptacknowledgement response, and generate the information. This providessuch an action that a data unit whose timing of output to an applicationin a wireless communication apparatus being a transmission destinationhas come is identified as a data unit that does not require the receiptacknowledgement response.

Further, in the first aspect, the control unit may determine that thetiming has come by measuring an elapsed time after transmission of theplurality of data units. This provides such an action that the fact thatthe timing has come is determined by measuring an elapsed time after thetransmission.

Further, in the first aspect, the control unit may specify the dataunit, the data unit being the last transmitted data unit in the dataunits that are consecutively transmitted and do not require the receiptacknowledgement responses, as a data unit that does not require thereceipt acknowledgement response. This provides such an action that adata unit that does not require the receipt acknowledgement response isspecified by the last transmitted data unit in the data units that areconsecutively transmitted and do not require the receipt acknowledgementresponses.

Further, in the first aspect, the control unit may specify a data unitthat requires the receipt acknowledgement response by using sequencenumbers provided to the plurality of transmitted data units. Thisprovides such an action that a data unit that requires the receiptacknowledgement response is identified by the sequence numbers.

Further, a second aspect of the present technology is a wirelesscommunication apparatus including: a reception unit that receives aplurality of data units and a receipt acknowledgement request includinginformation, the information specifying a data unit that requires areceipt acknowledgement response in the plurality of data units; and acontrol unit that controls, upon reception of a data unit other than thedata unit that requires the receipt acknowledgement response based onthe received receipt acknowledgement request, output of the data unit toan application. This provides such an action that a data unit other thanthe data unit that requires the receipt acknowledgement response isoutput to the application.

Further, in the second aspect, the control unit may further controltransmission of a receipt acknowledgement for only the data unit in theplurality of received data units that requires the receiptacknowledgement response based on the received receipt acknowledgementrequest. This provides such an action that a receipt acknowledgement forthe data unit that does not require the receipt acknowledgement responseis not performed.

Advantageous Effects of Invention

According to the present technology, a data unit that requires a receiptacknowledgement response in a plurality of transmitted data units issuitably selected, so that an optimal effect of improving conveniencemay be produced. It should be noted that the effects described hereinare not necessarily limited and may be any one of the effects describedherein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a configuration example of a wirelesscommunication system 10 in an embodiment of the present technology.

FIG. 2 is a diagram showing a configuration example of a wirelesscommunication apparatus (AP) 100 in the embodiment of the presenttechnology.

FIG. 3 is a diagram showing an example of a priority of a data unit inthe embodiment of the present technology.

FIG. 4 is a diagram showing an example of the data unit for which thepriority is set in the embodiment of the present technology.

FIG. 5 is a diagram showing an example of a relationship between thepriority and a data unit that requires a receipt acknowledgementresponse in the embodiment of the present technology.

FIG. 6 is a diagram schematically showing the exchange of frames betweenthe wireless communication apparatuses in the embodiment of the presenttechnology.

FIG. 7 is a diagram showing an example of a block ACK request frame inthe embodiment of the present technology.

FIG. 8 is a diagram showing another example of the block ACK requestframe in the embodiment of the present technology.

FIG. 9 is a diagram showing an example of a block ACK frame in theembodiment of the present technology.

FIG. 10 is a diagram showing an example of the processing procedure ofdata transmission processing in the embodiment of the presenttechnology.

FIG. 11 is a diagram showing an example of the processing procedure ofdata reception processing in the embodiment of the present technology.

FIG. 12 is a block diagram showing an example of a schematicconfiguration of a smartphone 900 to which the technology according tothe present disclosure is applicable.

FIG. 13 is a block diagram showing an example of a schematicconfiguration of a car navigation apparatus 920 to which the technologyaccording to the present disclosure is applicable.

FIG. 14 is a block diagram showing an example of a schematicconfiguration of a wireless access point 950 to which the technologyaccording to the present disclosure is applicable.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, a mode for carrying out the present technology(hereinafter, referred to as embodiment) will be described. Descriptionwill be given in the following order.

1. Embodiment (example of transmitting block ACK request frame includinginformation specifying data unit that requires ACK response)

2. Application Example

1. Embodiment Configuration of Wireless Communication System

FIG. 1 is a diagram showing a configuration example of a wirelesscommunication system 10 in an embodiment of the present technology. Thiswireless communication system 10 is a wireless network including awireless communication apparatus (AP) 100, a wireless communicationapparatus (STA) 200, a wireless communication apparatus (STA) 210, and awireless communication apparatus (STA) 220.

For example, the wireless communication system 10 may be a network(e.g., mesh network or ad hoc network) in which a plurality of devicesperform one-on-one wireless communication to thus be connected to oneanother.

Further, for example, the wireless communication apparatus (AP) 100 maybe an access point in a wireless LAN (Local Area Network) system. Inthis case, the wireless communication apparatus (STA) 200, the wirelesscommunication apparatus (STA) 210, and the wireless communicationapparatus (STA) 220 execute wireless communication under the rule of thewireless communication apparatus (AP) 100.

In FIG. 1, the apparatuses capable of directly communicating with oneanother using the wireless communication are connected by dotted lines.In other words, the wireless communication apparatus (AP) 100 is capableof communicating with the wireless communication apparatus (STA) 200,the wireless communication apparatus (STA) 210, and the wirelesscommunication apparatus (STA) 220. The wireless communication apparatus(STA) 200 is capable of communicating with the wireless communicationapparatus (AP) 100 and the wireless communication apparatus (STA) 210.The wireless communication apparatus (STA) 210 is capable ofcommunicating with the wireless communication apparatus (STA) 200, thewireless communication apparatus (AP) 100, and the wirelesscommunication apparatus (STA) 220. The wireless communication apparatus(STA) 220 is capable of communicating with the wireless communicationapparatus (STA) 210 and the wireless communication apparatus (AP) 100.

Configuration of Wireless Communication System

FIG. 2 is a diagram showing a configuration example of the wirelesscommunication apparatus (AP) 100 in the embodiment of the presenttechnology. It should be noted that each configuration of the wirelesscommunication apparatus (STA) 200, the wireless communication apparatus(STA) 210, and the wireless communication apparatus (STA) 220, whichhave been described in FIG. 1, can be similar to the configuration ofthe wireless communication apparatus (AP) 100 of FIG. 1.

The wireless communication apparatus (AP) 100 includes an Internetconnection unit 21, an information input unit 22, and a device controlunit 23. The wireless communication apparatuses (STA) 200, 210, and 220each include the information input unit 22, the device control unit 23,and an information output unit 24 as needed.

The Internet connection unit 21 performs connection with the Internet.

The information input unit 22 receives an input from a user. Theinformation input unit 22 receives an input from, for example, akeyboard or a touch panel.

The information output unit 24 outputs transmitted/received applicationdata to the user. The information output unit 24 is capable ofoutputting, for example, video information or voice information as data.

The device control unit 23 controls the wireless communication apparatus(AP) 100 and the whole of the wireless communication apparatuses (STA)200, 210, and 220. Further, the device control unit 23 includes anapplication for using data exchanged via the wireless communication.Examples of the application include an application for causing theinformation output unit 24 to display received image data. Further, theapplication corresponds to the application layer in a communicationnetwork and to a higher layer of a wireless communication module to bedescribed later.

Further, each of the wireless communication apparatus (AP) 100 and thewireless communication apparatuses (STA) 200, 210, and 220 furtherincludes an interface unit 101, a transmission buffer 102, a receptionbuffer 104, a transmission frame creation unit 105, and a wirelesssignal transmission processing unit 106. Further, each of the wirelesscommunication apparatus (AP) 100 and the wireless communicationapparatuses (STA) 200, 210, and 220 further includes a reception frameextraction unit 107, a wireless signal reception processing unit 108, anantenna control unit 109, and antenna elements 111 and 112. Each ofthose units can be achieved by, for example, a wireless communicationmodule specialized for the wireless communication.

Further, each of the wireless communication apparatus (AP) 100 and thewireless communication apparatuses (STA) 200, 210, and 220 furtherincludes a sequence management unit 103, a block ACK request sequencesetting unit 121, and a block ACK request sequence determination unit122. Further, each of the wireless communication apparatus (AP) 100 andthe wireless communication apparatuses (STA) 200, 210, and 220 furtherincludes a block ACK transmission unit 123, a block ACK reception unit124, a traffic determination unit 125, and an access control unit 126.

Here, the sequence management unit 103, the block ACK request sequencesetting unit 121, the block ACK request sequence determination unit 122,the block ACK transmission unit 123, and the block ACK reception unit124 constitute the control unit 120. The control unit 120 furtherincludes the traffic determination unit 125 and the access control unit126.

The interface unit 101 is an interface that inputs data to betransmitted by wireless communication from the user and outputs datareceived by the wireless communication to the user. The interface unit101 outputs data to be transmitted to the transmission buffer 102 andacquires received data from the reception buffer 104.

The transmission buffer 102 is a buffer that temporarily holds data tobe transmitted to another wireless communication apparatus. Thetransmission buffer 102 in FIG. 2 holds data input from the devicecontrol unit 23 via the interface unit 101.

The reception buffer 104 is a buffer that temporarily holds datareceived from another wireless communication apparatus. The receptionbuffer 104 in FIG. 2 takes a data unit to be described later from a dataframe and holds the data unit, the data frame being output from thereception frame extraction unit 107 to be described later.

The sequence management unit 103 manages a sequence number and apriority of the data held by the transmission buffer 102. Here, thesequence number is a number provided to each data unit to betransmitted/received. Further, the data unit is a unit of data managedon the basis of the priority or the like.

Further, the sequence management unit 103 causes the transmission framecreation unit 105 to output and transmit the data unit held in thetransmission buffer 102. The transmission frame creation unit 105 willbe described later. The output of the data unit is performed in order ofsequence number. Subsequently, the sequence management unit 103 deletesfrom the transmission buffer 102 a data unit that does not require areceipt acknowledgement response, which is determined by the block ACKrequest sequence setting unit 121 to be described later. Meanwhile, thesequence management unit 103 causes the transmission buffer 102 tocontinuously hold a data unit that requires a receipt acknowledgementresponse, which is determined by the block ACK request sequence settingunit 121, in preparation for retransmission when a transmission erroroccurs. When a data unit causing a transmission error is identified inthe block ACK reception unit 124 to be described later, the sequencemanagement unit 103 controls retransmission of that data unit.

Further, the sequence management unit 103 controls output of thereceived data to an application as a higher layer. Specifically, thesequence management unit 103 controls output of the data held in thereception buffer 104 to an application of the device control unit 23.This output is performed in order of sequence number. Among data unitsthat fail to be received due to transmission errors, data units thatrequire receipt acknowledgement responses are output to the applicationafter retransmission thereof. Also in this case, the data units areoutput in order of sequence number. Among the data units held in thereception buffer 104, data units whose timing of output to theapplication has come are output to the application even in the casewhere the data units are not consecutive in order of sequence number.Meanwhile, in the case where data units that do not require receiptacknowledgement responses, which are identified in the block ACK requestsequence determination unit 122 to be described later, are held in thereception buffer 104, the sequence management unit 103 outputs thosedata units before the timing described above comes. In this case, thedata units can be output in order of sequence number.

The transmission frame creation unit 105 creates a frame to betransmitted on the basis of a predetermined format and outputs the frameto the wireless signal transmission processing unit 106. Thetransmission frame creation unit 105 creates a frame that transmits dataoutput from the transmission buffer 102. For the frame that transmitsdata, an A-MPDU frame in which a plurality of data frames (MAC frames)are aggregated can be employed, in addition to the data frame.

Further, the transmission frame creation unit 105 further creates ablock ACK request frame. The block ACK request frame is a frame thatrequests receipt acknowledgement processing for the plurality of dataunits previously transmitted. The transmission frame creation unit 105generates a block ACK request frame on the basis of informationspecifying a data unit that requires a receipt acknowledgement response,the information being output from the block ACK request sequence settingunit 121 to be described later. Further, the transmission frame creationunit 105 further creates a block ACK frame. The block ACK frame is aframe that collectively performs a plurality of receipt acknowledgementresponses. The transmission frame creation unit 105 creates the blockACK frame on the basis of receipt acknowledgement information that isoutput from the block ACK transmission unit 123 to be described later.Detailed configurations of the block ACK request frame and the block ACKframe will be described later.

The wireless signal transmission processing unit 106 uses a frame to betransmitted as a baseband signal, to convert it into a high-frequencysignal.

The antenna control unit 109 controls the antenna elements 111 and 112.

The antenna elements 111 and 112 transmit signals to a wirelesstransmission path and receives signals from the wireless transmissionpath.

The wireless signal reception processing unit 108 extracts the basebandsignal from the high-frequency signal received via the antenna elements111 and 112 and outputs the baseband signal to the reception frameextraction unit 107. It should be noted that the wireless signalreception processing unit 108 is an example of a reception unitdescribed in the Claims.

The reception frame extraction unit 107 extracts frames from thebaseband signal. The reception frame extraction unit 107 in FIG. 2extracts the data frame, the block ACK request frame, and the block ACKframe and outputs those frames to the reception buffer 104, the blockACK request sequence determination unit 122, and the block ACK receptionunit 124, respectively.

The block ACK request sequence setting unit 121 specifies a data unitthat requires a receipt acknowledgement response in a wirelesscommunication apparatus as a transmission destination. This specifyingcan be performed by, for example, specifying a sequence number of thedata unit that requires a receipt acknowledgement response. The blockACK request sequence setting unit 121 generates information to specifythe data unit that requires a receipt acknowledgement response, andoutputs the information to the transmission frame creation unit 105.Further, the block ACK request sequence setting unit 121 is also capableof changing the number of data units that require receiptacknowledgement responses and adjusting a transmission delay. A dataunit that requires a receipt acknowledgement response can be specifiedaccording to the priority of the data unit, for example. In other words,for a data unit having a high priority, a receipt acknowledgementresponse can be requested and the retransmission of the data unit can beperformed on the basis of the returned receipt acknowledgement. Incontrast, for a data unit having a low priority, the request of thereceipt acknowledgement response can be omitted. Further, even in thecase where a response indicates that the data unit is not received inthe transmission destination of the data unit, retransmission processingcan be omitted for a data unit having a low priority. This can improvethe throughput of transmission of data units.

Further, the data unit that requires a receipt acknowledgement responsecan be specified according to a situation of the wireless transmissionpath. For example, in the case where the wireless transmission path iscongested, the number of data units that request receipt acknowledgementresponses can be changed. Specifically, in the case where the wirelesstransmission path is congested, the number of data units that requestreceipt acknowledgement responses can be reduced. For example, among aplurality of transmitted data units, data units early transmitted can beconsidered as data units that do not require receipt acknowledgementresponses irrespective of the priority and can be excluded from thespecified data units that require receipt acknowledgement responses.Thus, even in the case where the wireless transmission path iscongested, the throughput of data transmission can be prevented fromdecreasing. In this case, the block ACK request sequence setting unit121 determines a situation of the wireless transmission path on thebasis of a congestion degree determined by the traffic determinationunit 125.

Further, the data unit that requires a receipt acknowledgement responsecan be specified according to a situation of the transmission buffer102. For example, when the data units held in the transmission buffer102 reach a predetermined amount, the number of data units that requestreceipt acknowledgement responses can be changed. Specifically, when thedata units held in the transmission buffer 102 reach a predeterminedamount, the number of data units that request receipt acknowledgementresponses can be reduced. In this case, irrespective of the priority,the transmitted data units can be changed to data units that do notrequire receipt acknowledgement responses, thus omitting the processingfor receipt acknowledgement and retransmission. Thus, the data unitsheld in the transmission buffer 102 in preparation for retransmissioncan be deleted. It should be noted that, for the predetermined amountdescribed above, for example, a value of 80% of a permissible dataamount of the transmission buffer 102 can be set in advance for use.

Further, a data unit whose timing of output to the application in thewireless communication apparatus as a transmission destination of thedata unit has come can be set as a data unit that does not require areceipt acknowledgement response. For example, in the case where theapplication performs display of an image based on the data received inthe wireless communication apparatus as a transmission destination, atiming at which image data in this application is to be displayed can beset to a timing at which the image data is to be output to theapplication described above. In order to acquire this timing, a timerfor measuring an elapsed time after the transmission of the data unitcan be used. Thus, real-time properties in the application of thetransmission destination can be improved. Further, the wirelesscommunication apparatus as a transmission destination of the data unitcan be notified of the fact that a timing of output to the applicationhas come.

The access control unit 126 controls communication with anothercommunication apparatus on the wireless transmission path in conformityto a predetermined communication protocol.

The traffic determination unit 125 determines the congestion degree ofthe wireless transmission path.

The block ACK request sequence determination unit 122 identifies dataunits that require receipt acknowledgement responses and data units thatdo not require receipt acknowledgement responses, on the basis of thereceived block ACK request frame.

The block ACK transmission unit 123 performs receipt acknowledgement ofthe data units that require receipt acknowledgement responses, the dataunits being identified in the block ACK request sequence determinationunit 122. Further, the block ACK transmission unit 123 generates resultsof the receipt acknowledgement as receipt acknowledgement informationand outputs the receipt acknowledgement information to the transmissionframe creation unit 105.

The block ACK reception unit 124 analyzes the received block ACK frameand identifies a data unit causing a transmission error.

Priority of Data Unit

FIG. 3 is a diagram showing an example of the priority of the data unitin the embodiment of the present technology. As described above, in theembodiment of the present technology, it is determined whether a dataunit requires a receipt acknowledgement response or not according to thepriority. As shown in FIG. 3, the priority defined in the wireless LANstandard of IEEE (Institute of Electrical and Electronic Engineers)802.11 can be applied to the above priority. In IEEE802.11D, “NetworkControl”, “Voice”, “Video”, “Controlled Load”, “Excellent Effort”, “BestEffort”, and “Background” are defined as User Priority in descendingorder of priority. Further, in IEEE802.11e, “Voice”, “Video”, “BestEffort”, and “Background” are defined as Access Category in descendingorder of priority. Those priorities can be applied to the data units.

In such a manner, a data unit having high importance such as systemcontrol data or voice data corresponds to the data unit having a highpriority. A data unit having low importance such as a background imagecorresponds to the data unit having a low priority. It should be notedthat the priority is not limited to this example, and another index canalso be used therefor.

Priority Setting

FIG. 4 is a diagram showing an example of a data unit for which thepriority is set in the embodiment of the present technology. FIG. 4shows a case where the priority is set for a data unit held in thetransmission buffer 102 described in FIG. 2. FIG. 4 assumes a case wherethe priorities of three levels are set for data units. Since data unitshaving sequence numbers 1, 4, 7, and 10 have a data type of “Voice”, thepriority 1 of the highest priority is set therefor. Since data unitshaving sequence numbers 2, 5, 8, and 11 have a data type of “Video”, thepriority 2 of the second highest priority is set therefor. Since dataunits having sequence numbers 3, 6, 9, and 12 have a data type of “BestEffort”, the priority 3 of the lowest priority is set therefor. Itshould be noted that the priority 3 can also be set for the case wherethe data type is “Background”. This priority setting is performed by thesequence management unit 103 described in FIG. 2.

It should be noted that the priority setting is not limited to thisexample. For example, the priorities of four levels or more can be setfor data units.

Relationship Between Priority and Data Unit that Requires ReceiptAcknowledgement Response

FIG. 5 is a diagram showing an example of a relationship between thepriority and a data unit that requires a receipt acknowledgementresponse in the embodiment of the present technology. FIG. 5 shows arelationship between a reference priority and a priority of a data unitthat requires a receipt acknowledgement response. Here, the referencepriority is a reference regarding the necessity of a receiptacknowledgement response. In FIG. 5, a data unit having a priorityhigher than a reference priority is assumed as a data unit that requiresa receipt acknowledgement response. Specifically, in the case where thereference priority is 1, the data unit of the priority 1 corresponds toa data unit that requires a receipt acknowledgement response. Thesequence numbers of the data units corresponding thereto are 1, 4, 7,and 10. The data units having the other sequence numbers correspond todata units that do not require receipt acknowledgement responses. Thosedata units are not subjected to the retransmission processing. In thecase where the reference priority is 2, the data units of the priorities1 and 2 correspond to data units that require receipt acknowledgementresponses. The sequence numbers of the data units corresponding theretoare 1, 2, 4, 5, 7, 8, 10, and 11. In the case where the referencepriority is 3, the data units of all the priorities correspond to dataunits that require receipt acknowledgement responses.

The reference priority can be changed according to a situation aftertransmission of the data units. For example, the reference priority canbe changed according to a situation of the wireless transmission path.For example, the reference priority can be changed according to an errorrate of the wireless transmission path. For example, when the error rateof the wireless transmission path rises, the reference priority can bechanged. Specifically, when the error rate of the wireless transmissionpath rises, the reference priority can be changed to a lower priority.Performing response and retransmission of the receipt acknowledgementfor the data unit having a lower priority can cause more data units toreach a wireless communication apparatus on the reception side even whenthe error rate rises.

Further, for example, the reference priority can be changed according tothe congestion degree of the wireless transmission path. For example,when the wireless transmission path is congested, the reference prioritycan be changed. Specifically, when the wireless transmission path iscongested, the reference priority can be changed to a higher priority.Limiting data units that require the response and retransmissionprocessing for receipt acknowledgements can prevent the throughput ofdata transmission from decreasing. Meanwhile, when the wirelesstransmission path is not congested, the reference priority can bechanged to a lower priority, so that a receipt acknowledgement responsecan be requested for many data units.

Further, for example, the reference priority can also be changedaccording to a situation of the transmission buffer 102. For example,when the data units held in the transmission buffer 102 described inFIG. 2 reach a predetermined amount, the reference priority can bechanged. Specifically, when the data units held in the transmissionbuffer 102 reach a predetermined amount, the reference priority can bechanged to a higher priority. Thus, the data units held in thetransmission buffer 102 in preparation for retransmission processing canbe deleted.

In such a manner, the reference priority is changed when the situationof the wireless transmission path or the transmission buffer 102 ischanged, so that a data unit that requires a receipt acknowledgement canbe selected on the basis of the reference priority set in advance andthe processing can be simplified.

Wireless Communication Sequence

FIG. 6 is a diagram schematically showing the exchange of frames betweenthe wireless communication apparatuses in the embodiment of the presenttechnology. FIG. 6 is a sequence diagram showing the exchange of data tobe transmitted from the wireless communication apparatus on thetransmission side (wireless communication apparatus (AP) 100) to thewireless communication apparatus on the reception side (wirelesscommunication apparatus (STA) 200). It should be noted that the samesequence is performed also in the case where data is transmitted fromthe wireless communication apparatus on the transmission side (wirelesscommunication apparatus (STA) 200 to the wireless communicationapparatus on the reception side (wireless communication apparatus(AP100).

First, a data unit 1 is output from an application 190 as an applicationon the transmission side to the wireless communication apparatus 100(301). Here, the “data unit 1” represents a data unit provided with thevalue “1” as a sequence number. Further, a “priority 1” in FIG. 6indicates that the priority of the data unit 1 has the value “1”. Insuch a manner, the sequence management unit 103 sequentially givessequence numbers to data units, which are output from the application asa transmission destination, and for which the priorities are set.

Next, when the data unit 1 is output, the transmission frame creationunit 105 of the wireless communication apparatus 100 creates a dataframe including the data unit 1, and the data frame is transmitted tothe wireless communication apparatus 200 (309). Here, the rectangle inFIG. 6 represents a frame. Further, a frame type is given to therectangle. For example, frames to which “data”, “block ACK request”, and“block ACK” are given represent a data frame, a block ACK request frame,and a block ACK frame, respectively. It should be noted that “data (1)”represents a data frame corresponding to the data unit with the sequencenumber of the value “1”.

In a similar manner, data units 2 to 8 are sequentially output from theapplication 190 to the wireless communication apparatus 100 (302 to308). Every time those data units are output, the wireless communicationapparatus 100 transmits data frames (310 to 316). In FIG. 6, thefollowing case is assumed: among the transmitted data frames, the dataframes including the data units with the sequence numbers 3 and 7 do notreach the wireless communication apparatus 200 due to transmissionerrors.

Subsequently, the wireless communication apparatus 100 transmits a blockACK request frame (317). Here, in a “block ACK request (1 to 8: 1, 4,7)” in FIG. 6, “1 to 8” in the parentheses represents the range of thesequence numbers of the data units that are targets for the block ACKrequest, and the numbers subsequent to “:” in the parentheses eachrepresent a sequence number of a data unit that requires a receiptacknowledgement response. In other words, the block ACK request frame inFIG. 6 indicates that the data units with the sequence numbers 1 to 8are targets for the block ACK request and that the data units with thesequence numbers 1, 4, and 7 among them are data units that requirereceipt acknowledgement responses. In FIG. 6, the following case isassumed: the wireless communication apparatus 100 sets 1 for thereference priority described in FIG. 5.

The wireless communication apparatus 200, which receives the block ACKrequest frame, grasps the data units that require receiptacknowledgement responses among the received data units, and identifiesa data unit that does not require a receipt acknowledgement response.This is performed by the block ACK request sequence determination unit122. In FIG. 6, among the received data units, data units that do notrequire receipt acknowledgement responses are data units with thesequence numbers 2, 5, 6, and 8. Further, among the data units with thesequence numbers 3 and 7, which cause transmission errors, the data unitwith the sequence number 3 corresponds to a data unit that does notrequire a receipt acknowledgement response, and the data unit with thesequence number 7 corresponds to a data unit that requires a receiptacknowledgement response. Subsequently, the wireless communicationapparatus 200 outputs the data units to an application 290 in order ofsequence number, the data units excluding the data unit with thesequence number 3, which is not received and does not require a receiptacknowledgement return. In other words, the data units with the sequencenumbers 1, 2, and 4 to 6 are sequentially output to the application 290(318 to 322).

Meanwhile, the wireless communication apparatus 200 transmits a blockACK frame to the wireless communication apparatus 100 (323). Here, in a“block ACK (1, 4: ACK, 7: NG)” in FIG. 6, “1, 4: ACK” in the parenthesesrepresents the fact that the data units with the sequence numbers 1 and4 are received, and “7: NG” in the parentheses represents the fact thatthe data unit with the sequence number 7 is not received. The wirelesscommunication apparatus 100, which has received this block ACK frame,retransmits the data frame of the sequence number 7 (324). Subsequently,data units 9 to 12 are sequentially output from the application 190 tothe wireless communication apparatus 100 (325 to 328). The wirelesscommunication apparatus 100 creates data frames from those data units totransmit them (329 to 332). In FIG. 6, the following case is assumed:among the transmitted data frames, the data frames including the dataunits with the sequence numbers 9 and 12 do not reach the wirelesscommunication apparatus 200 due to transmission errors.

Subsequently, the wireless communication apparatus 100 transmits a blockACK request frame (333). The block ACK request frame indicates that thedata units with the sequence numbers 7 to 12 are targets for the blockACK request and that the data units with the sequence numbers 7, 10, and11 are data units that require receipt acknowledgement responses. Sincetransmission errors are caused in the previous transmission of the dataframes, the wireless communication apparatus 100 determines that theerror rate of the wireless transmission path rises and thus changes thereference priority from 1 to 2. Thus, a receipt acknowledgement responseis requested also for the data unit with the sequence number 11(priority 2).

The wireless communication apparatus 200, which has received this frame,determines that the retransmission processing is not to be performed forthe data units with the sequence numbers 9 and 12 and outputs the dataunits with the sequence numbers 7, 8, 10, and 11 to the application 290(334 to 337). Further, the wireless communication apparatus 200transmits a block ACK frame indicating the fact that the data units withthe sequence numbers 7, 10, and 11 are received to the wirelesscommunication apparatus 100 (338).

It should be noted that, in FIG. 6, a plurality of data units aretransmitted as individual data frames when transmitted from the wirelesscommunication apparatus 100, but an A-MPDU frame that aggregates thedata units can be created for transmission. Further, the frame can alsobe transmitted by multicasting.

Block ACK Request Frame

FIG. 7 is a diagram showing an example of the block ACK request frame inthe embodiment of the present technology. The block ACK request frame inFIG. 7 includes MAC Header 400, BAR (Block Ack Request) Control 401, BARInformation 402, and FCS (Frame Check Sequence) 403. The FCS 403 is afield in which an error-detecting code is stored.

The MAC Header 400 stores an object for frame transmission and the like.The MAC Header 400 includes Frame Control, Duration/ID, RA (ReceiverAddress), and TA (Transmitter Address). The Frame Control storesinformation such as a frame type. The Duration/ID stores a duration oridentifier of the frame. The RA stores the address of a receptiondestination of the frame. The TA stores the address of a transmissionsource of the frame.

The BAR Control 401 stores parameters of the block ACK request frame andthe like. The BAR Control 401 in FIG. 7 stores BAR Ack Policy 404,Multi-TID 405, Compressed Bitmap 406, Priority BAR Request 407, andTID_INFO 409. Of those, the Priority BAR Request 407 stores anidentifier indicating a block ACK request frame including informationspecifying a data unit that requires a receipt acknowledgement response.It should be noted that Reserved 408 in FIG. 7 is an unused field.

The BAR Information 402 stores information specifying a data unit thatrequires a receipt acknowledgement response, and the like. The BARInformation 402 in FIG. 7 stores BAR Info Length 410, Start SequenceNumber 411, and Current Sequence Number 412. Further, the BARInformation 402 in FIG. 7 further stores Desired ACK Bitmap 413. The BARInfo Length 410 stores the length of the field. The Start SequenceNumber 411 stores a start sequence number. The Current Sequence Number412 stores an end sequence number. The Desired ACK Bitmap 413 stores, asdata in a bitmap format, information specifying a data unit thatrequires a receipt acknowledgement response.

In the block ACK request frame in FIG. 7, the Start Sequence Number 411and the Current Sequence Number 412 indicate the range of data unitsthat are targets for the block ACK request frame. Of those, a data unitthat requires a receipt acknowledgement response can be specified bychanging a bit corresponding to the file stored in the Desired ACKBitmap 413 to the value “1”, for example.

Another Example of Block ACK Request Frame

FIG. 8 is a diagram showing another example of the block ACK requestframe in the embodiment of the present technology. The block ACK requestframe in FIG. 8 is a simplified one of the block ACK request framedescribed in FIG. 7 and is different from the block ACK request framedescribed in FIG. 7 in the configuration of the BAR Information 402.

The BAR Information 402 in FIG. 8 stores Identifire 414, Start SequenceNumber 415, and End Sequence Number 416. Further, the BAR Information402 in FIG. 8 further stores Current Sequence Number 417. The Identifire414 stores an identifier indicating a simplified block ACK requestframe. For example, the Identifire 414 stores “0” of a 1-octet length.The Start Sequence Number 415 stores a start sequence number as with theblock ACK request frame of FIG. 7. The End Sequence Number 416 stores anend sequence number of a data unit that does not require a receiptacknowledgement response. The Current Sequence Number 417 stores an endsequence number as with the block ACK request frame of FIG. 7.

Also in the block ACK request frame in FIG. 8, the Start Sequence Number415 and the Current Sequence Number 417 indicate the range of data unitsthat are targets for the block ACK request frame. Of those, data unitsthat do not require receipt acknowledgement responses correspond to dataunits in the range indicated by the Start Sequence Number 415 and theEnd Sequence Number 416. In other words, among the data units as targetsfor the block ACK request frame, the data units up to the End SequenceNumber 416 correspond to data units that do not require receiptacknowledgement responses. Meanwhile, the data units from a sequencenumber subsequent to the number stored in the End Sequence Number 416 tothe sequence number stored in the Current Sequence Number 417 correspondto data units that require receipt acknowledgement responses.

The block ACK request frame in FIG. 8 specifies a data unit, which isthe last transmitted data unit in the data units that are consecutivelytransmitted and do not require receipt acknowledgement responses, as adata unit that does not require a receipt acknowledgement response. Theblock ACK request frame in FIG. 8 can be used, for example, in the casewhere among a plurality of transmitted data units, data units earlytransmitted are collected and set as data that does not require areceipt acknowledgement response.

Other configurations are similar to those of the block ACK request framedescribed in FIG. 7, and description thereof will thus be omitted.

In such a manner, a bitmap file is unnecessary, and thus the block ACKframe in FIG. 8 can be easily created as compared with the block ACKrequest frame described in FIG. 7.

Example of Block ACK Frame

FIG. 9 is a diagram showing an example of the block ACK frame in theembodiment of the present technology. FIG. 9 shows a configuration ofthe block ACK frame defined in IEEE802.11-2012. This frame includes MACHeader 418, BA (Block Ack) Control 419, BA Information 420, and FCS 421.The MAC Header 418 and the FCS 421 are respectively similar to the MACHeader 400 and the FCS 403 described in FIG. 7, and description thereofwill thus be omitted.

The BA Control 419 includes BA Ack Policy 422, Multi-TID 423, CompressedBitmap 424, Reserved 425, and TID_INFO 426.

The BA Information 420 includes Block Ack Starting Sequence Control 427and Block Ack Bitmap 428. The Block Ack Starting Sequence Control 427stores a start sequence number of the block ACK frame. The Block AckBitmap 428 stores data in a bitmap format, which shows a result of thereceipt acknowledgement.

In the case where the block ACK frame in FIG. 9 is transmitted as aresponse to the block ACK request frame described in FIG. 8, theabove-mentioned start sequence number can be caused to correspond to thesequence number of the block ACK request frame. Specifically, the numbersubsequent to the sequence number of the End Sequence Number 416described in FIG. 8 can be set to the sequence number of the Block AckStarting Sequence Control 427 described above. Thus, the stored data ofthe Block Ack Bitmap 428 can be shortened.

Data Transmission Processing

FIG. 10 is a diagram showing an example of the processing procedure ofdata transmission processing in the embodiment of the presenttechnology. The processing in FIG. 10 is executed every timetransmission data is output from the application 190 to the wirelesscommunication apparatus (transmission side) 100. For the purpose ofconvenience, the “data unit” is simply described as “data” in thedescription of FIG. 10 and the following figures.

First, the wireless communication apparatus 100 determines whethertransmission data from the application 190 is received or not (StepS801). If the transmission data is received (Step S801: Yes), thewireless communication apparatus 100 stores data transmitted to thetransmission buffer 102 (Step S802). Next, the wireless communicationapparatus 100 sets the priority according to a data attribute (StepS803). Subsequently, the wireless communication apparatus 100 moves tothe processing of Step S804. Meanwhile, if the transmission data is notreceived in Step S801 (Step S801: No), the wireless communicationapparatus 100 skips the processing of Steps S802 and S803 and moves tothe processing of Step S804.

In Step S804, the wireless communication apparatus 100 determineswhether a transmission timing has come or not (Step S804). This can bedetermined on the basis of, for example, a data amount held in thetransmission buffer 102. If a transmission timing has not come (StepS804: No), the wireless communication apparatus 100 executes theprocessing from Step S801 again. If a transmission timing has come (StepS804: Yes), the wireless communication apparatus 100 acquires theinformation length of the transmission data (Step S805) and creates atransmission data frame (Step S806). Next, the wireless communicationapparatus 100 determines whether aggregation is enabled or not whentransmitting a plurality of data frames (Step S807). For example, thewireless communication apparatus 100 is capable of determining thataggregation is disabled when a predetermined information length isexceeded by the aggregation. This can be performed on the basis of theinformation length acquired in Step S805. Further, for example, thewireless communication apparatus 100 is capable of determining thataggregation is disabled also in the case where data to be aggregated isabsent.

As a result, if aggregation is enabled (Step S807: Yes), the wirelesscommunication apparatus 100 executes the processing from Step S805again. Meanwhile, if aggregation is disabled (Step S807: No), thewireless communication apparatus 100 determines whether the wirelesstransmission path is accessible or not (Step S808) and waits until thewireless transmission path becomes accessible. For example, the wirelesscommunication apparatus 100 is capable of determining that the wirelesstransmission path is accessible when a collision with thetransmission/reception of another wireless communication apparatus doesnot occur. If the wireless transmission path is accessible (Step S808:Yes), the wireless communication apparatus 100 transmits the data frame(Step S809) and registers a sequence number of the transmitted data unit(Step S810). This is performed by the sequence management unit 103described in FIG. 2.

Next, the wireless communication apparatus 100 determines whether areceipt acknowledgement timing has come or not (Step S811). For example,the wireless communication apparatus 100 is capable of determining thata receipt acknowledgement timing has come when the transmission of datawith a predetermined amount is complete. If a receipt acknowledgementtiming has not come (Step S811: No), the wireless communicationapparatus 100 moves to the processing of Step S819. Meanwhile, if areceipt acknowledgement timing has come (Step S811: Yes), the wirelesscommunication apparatus 100 acquires a state of the transmission buffer102 (Step S812) and acquires a situation of the wireless transmissionpath (Step S813). Next, the wireless communication apparatus 100determines the priority for which the receipt acknowledgement is to beperformed on the basis of those acquired situations and the like (StepS814). Thus, the reference priority described in FIG. 5 is set.

Next, the wireless communication apparatus 100 identifies the range ofsequence numbers that do not require receipt acknowledgements (StepS815), identifies sequence numbers that require receipt acknowledgements(Step S816), and creates and transmits a block ACK request frame (StepS817). Subsequently, the wireless communication apparatus 100 deletesdata that does not require a receipt acknowledgement from thetransmission buffer 102 (Step S818). Subsequently, the wirelesscommunication apparatus 100 moves to the processing of Step S819.

In Step S819, the wireless communication apparatus 100 determineswhether the block ACK frame is received or not (Step S819). If the blockACK frame is not received (Step S819: No), the wireless communicationapparatus 100 executes the processing from Step S801 again. If the blockACK frame is received (Step S819: Yes), the wireless communicationapparatus 100 determines whether data to be retransmitted is present ornot (Step S820). This can be determined on the basis of a result of thereceipt acknowledgement that is stored in the received block ACK frame.If data to be retransmitted is absent (Step S820: No), that is, if alldata that require receipt acknowledgements are received, the wirelesscommunication apparatus 100 deletes the data from the transmissionbuffer 102 (Step S822). Subsequently, the wireless communicationapparatus 100 executes the processing from Step S801 again.

In Step S820, if data to be retransmitted is present (Step S820: Yes),the wireless communication apparatus 100 creates a data frame to beretransmitted (Step S821). Next, the wireless communication apparatus100 moves to the processing of Step S808.

It should be noted that the processing of Step S817 is an example of atransmission procedure described in the Claims.

Data Reception Processing

FIG. 11 is a diagram showing an example of the processing procedure ofdata reception processing in the embodiment of the present technology.The processing in FIG. 11 shows reception processing in the wirelesscommunication apparatus (on the reception side) 200.

First, the wireless communication apparatus 200 waits until a frame isreceived (Step S851). If a frame is received (Step S851: Yes), thewireless communication apparatus 200 determines whether a data frame isreceived or not (Step S852). If a data frame is received without errors(Step S852: Yes), the wireless communication apparatus 200 extracts asequence number (Step S853). This can be performed by extracting asequence number stored in the MAC header of the received data frame.

Next, the wireless communication apparatus 200 determines whether theextracted sequence number is a newly received sequence number or not(Step S854). If the extracted sequence number is a newly receivedsequence number (Step S854: Yes), the wireless communication apparatus200 stores the received data in the reception buffer 104 (Step S855) andmoves to the processing of Step S856. Meanwhile, if the extractedsequence number is not a newly received sequence number (Step S854: No),the wireless communication apparatus 200 skips the processing of StepS855 and moves to the processing of Step S856.

In Step S856, the wireless communication apparatus 200 determineswhether the received data frame is an aggregated data frame or not (StepS856). If the received data frame is an aggregated data frame (StepS856: Yes), the wireless communication apparatus 200 executes theprocessing from Step S853 again. If the received data frame is not anaggregated data frame (Step S856: No), the wireless communicationapparatus 200 determines whether the sequence numbers of the data areconsecutive or not (Step S857).

If the sequence numbers of the data are consecutive (Step S857: Yes),the wireless communication apparatus 200 outputs the data having thoseconsecutive sequence numbers to the application 290 (Step S858).Subsequently, the wireless communication apparatus 200 deletes the dataoutput to the application 290 from the reception buffer 104 (Step S859)and executes the processing from Step S851 again. Meanwhile, if thesequence numbers of the data are not consecutive in Step S857, thewireless communication apparatus 200 skips the processing of Steps S858and S859 and moves to the processing of Step S851.

If the data frame is not received in Step S852 (Step S852: No), thewireless communication apparatus 200 determines whether a block ACKrequest frame is received or not (Step S860). If a block ACK requestframe is received (Step S860: Yes), the wireless communication apparatus200 identifies a sequence number for which the receipt acknowledgementis to be performed (Step S861). Next, the wireless communicationapparatus 200 creates receipt acknowledgement information of theidentified sequence number (Step S862). Next, the wireless communicationapparatus 200 waits until a block ACK frame can be transmitted (StepS863). If a block ACK frame can be transmitted (Step S863: Yes), thewireless communication apparatus 200 transmits the block ACK frame (StepS864).

Next, the wireless communication apparatus 200 determines whether datanot to be retransmitted is present or not (Step S865). This can bedetermined by identifying data that does not require a receiptacknowledgement response on the basis of the data for which the receiptacknowledgement is to be performed, which is identified in Step S861,and then determining whether such data is received or not. If data notto be retransmitted is absent, that is, if data that does not require areceipt acknowledgement response is absent (Step S865: No), the wirelesscommunication apparatus 200 moves to the processing of Step S857.Meanwhile, if data not to be retransmitted, that is, data that does notrequire a receipt acknowledgement response is present (Step S865: Yes),the wireless communication apparatus 200 outputs the data received up tothat sequence number to the application 290 (Step S867). Subsequently,the wireless communication apparatus 200 deletes the data output to theapplication 290 from the reception buffer 104 (Step S868) and executesthe processing from Step S851 again.

Meanwhile, if a block ACK request frame is not received in Step S860(Step S860: No), whether a timing to output the received data to theapplication 290 has come or not is determined (Step S866). This isdetermined by the sequence management unit 103 described in FIG. 2. If atiming to output the received data to the application 290 has not come(Step S866: No), the wireless communication apparatus 200 executes theprocessing from Step S851 again. Meanwhile, if a timing to output thereceived data to the application 290 has come (Step S866: Yes), thewireless communication apparatus 200 moves to the processing in StepS867.

It should be noted that the processing of Steps S852 and S860 is anexample of a reception procedure described in the Claims. The processingof Step S867 is an example of an output procedure described in theClaims.

In such a manner, according to the embodiment of the present technology,the convenience can be improved by suitably selecting a data unit thatrequires a receipt acknowledgement and notifying a transmissiondestination of the data unit according to a change in situation of thewireless transmission path or the like.

2. Application Example

The technology according to the present disclosure is applicable tovarious products. For example, the wireless communication apparatus(STA) 200 may be achieved as mobile terminals such as a smartphone, atablet PC (Personal Computer), a laptop PC, a portable game terminal,and a digital camera, fixed terminals such as a television receiver, aprinter, a digital scanner, and a network storage, or in-vehicleterminals such as a car navigation apparatus. Further, the wirelesscommunication apparatus (STA) 200 may be achieved as terminals thatperform M2M (Machine To Machine) communication (also referred to as MTC(Machine Type Communication) terminals), such as a smart meter, anautomatic vending machine, a remote monitoring apparatus, and POS (PointOf Sale) terminals. Furthermore, the wireless communication apparatus(STA) 200 may be a wireless communication module (e.g., an integratedcircuit module constituted by a single die) to be mounted onto thoseterminals.

Meanwhile, for example, the wireless communication apparatus (AP) 100may be achieved as a wireless LAN access point (also referred to aswireless base station) with a router function or without routerfunction. Further, the wireless communication apparatus (AP) 100 may beachieved as a mobile wireless LAN router. Furthermore, the wirelesscommunication apparatus (AP) 100 may be achieved as a wirelesscommunication module (e.g., an integrated circuit module constituted bya single die) to be mounted onto those apparatuses.

2-1. First Application Example

FIG. 12 is a block diagram showing an example of a schematicconfiguration of a smartphone 900 to which the technology according tothe present disclosure is applicable. The smartphone 900 includes aprocessor 901, a memory 902, a storage 903, an external connectioninterface 904, a camera 906, a sensor 907, a microphone 908, an inputdevice 909, a display device 910, a speaker 911, a wirelesscommunication interface 913, an antenna switch 914, an antenna 915, abus 917, a battery 918, and an auxiliary controller 919.

The processor 901 may be, for example, a CPU (Central Processing Unit)or a SoC (System on Chip) and controls the functions of the applicationlayer or other layers of the smartphone 900. The memory 902 includes aRAM (Random Access Memory) and a ROM (Read Only Memory) and storesprograms and data to be executed by the processor 901. The storage 903may include a storage medium such as a semiconductor memory or a harddisk. The external connection interface 904 is an interface forconnecting an external device such as a memory card or a USB (UniversalSerial Bus) device to the smartphone 900.

The camera 906 includes, for example, an imaging device such as a CCD(Charge Coupled Device) or a CMOS (Complementary Metal OxideSemiconductor) and generates a captured image. The sensor 907 mayinclude, for example, a sensor group including a positioning sensor, agyro sensor, a geomagnetic sensor, an acceleration sensor, and the like.The microphone 908 converts sound input to the smartphone 900 into asound signal. The input device 909 includes, for example, a touch sensorthat detects a touch on the screen of the display device 910, a key pad,a keyboard, a button, a switch, or the like and receives an operation ofa user or an input of information. The display device 910 includes ascreen of a liquid crystal display (LCD), an organic light-emittingdiode (OLED) display, or the like and displays an output image of thesmartphone 900. The speaker 911 converts a sound signal output from thesmartphone 900 into sound.

The wireless communication interface 913 supports one or more wirelessLAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad andexecutes wireless communication. The wireless communication interface913 may communicate with another apparatus via a wireless LAN accesspoint in an infrastructure mode. Further, the wireless communicationinterface 913 may directly communicate with another apparatus in adirect communication mode such as an ad hoc mode or Wi-Fi Direct. Itshould be noted that one of two terminals operates as an access point inthe Wi-Fi Direct, unlike the ad hoc mode, but the communication isdirectly performed between those terminals. Typically, the wirelesscommunication interface 913 may include a baseband processor, an RF(Radio Frequency) circuit, a power amplifier, and the like. The wirelesscommunication interface 913 may be a memory that stores a communicationcontrol program, a processor that executes the program, or a one-chipmodule that integrates related circuits. The wireless communicationinterface 913 may support, in addition to the wireless LAN system, othertypes of wireless communication systems such as a near field wirelesscommunication system, a close proximity wireless communication system,and a cellular communication system. The antenna switch 914 switches aconnection destination of the antenna 915 between a plurality ofcircuits (e.g., circuits for different wireless communication systems)included in the wireless communication interface 913. The antenna 915includes a single or a plurality of antenna elements (e.g., a pluralityof antenna elements constituting MIMO antenna) and is used for thewireless communication interface 913 to transmit and receive a wirelesssignal.

It should be noted that the smartphone 900 is not limited to the exampleof FIG. 12 and may include a plurality of antennas (e.g., antenna forwireless LAN or antenna for close proximity wireless communicationsystem). In such a case, the antenna switch 914 may be omitted from theconfiguration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 913, and the auxiliarycontroller 919 to one another. The battery 918 supplies power to eachblock of the smartphone 900 shown in FIG. 12 via feed lines partiallyshown by broken lines in the figure. The auxiliary controller 919operates the bare minimum of functions of the smartphone 900 in a sleepmode, for example.

In the smartphone 900 shown in FIG. 12, the control unit 120 describedwith reference to FIG. 2 may be implemented in the wirelesscommunication interface 913. Further, at least part of those functionsmay be implemented in the processor 901 or auxiliary controller 919. Forexample, when the smartphone 900 transmits the block ACK request framedescribed in FIGS. 7 and 8, the retransmission processing for a dataunit that does not require a receipt acknowledgement return can beeliminated, and power consumption of the battery 918 can be reduced.Further, when a data unit that requires a receipt acknowledgement issuitably selected and a transmission destination is notified of the dataunit according to a change in situation of the wireless transmissionpath or the like, the convenience can be improved.

It should be noted that the smartphone 900 may operate as a wirelessaccess point (software AP) when the processor 901 executes the accesspoint function at the application level. Further, the wirelesscommunication interface 913 may have a wireless access point function.

2-2. Second Application Example

FIG. 13 is a block diagram showing an example of a schematicconfiguration of a car navigation apparatus 920 to which the technologyaccording to the present disclosure is applicable. The car navigationapparatus 920 includes a processor 921, a memory 922, a GPS (GlobalPositioning System) module 924, a sensor 925, a data interface 926, acontent player 927, a storage medium interface 928, an input device 929,a display device 930, a speaker 931, a wireless communication interface933, an antenna switch 934, an antenna 935, and a battery 938.

The processor 921 may be, for example, a CPU or a SoC and controls anavigation function and other functions of the car navigation apparatus920. The memory 922 includes a RAM and a ROM and stores programs anddata to be executed by the processor 921.

The GPS module 924 measures a position of the car navigation apparatus920 (e.g., latitude, longitude, and altitude) by using a GPS signalreceived from a GPS satellite. The sensor 925 may include, for example,a sensor group including a gyro sensor, a geomagnetic sensor, and apneumatic sensor, and the like. For example, the data interface 926 isconnected to an in-vehicle network 941 via a terminal (not shown) andacquires data generated on the vehicle side, such as vehicle speed data.

The content player 927 reproduces the content stored in a storage medium(e.g., CD or DVD) to be inserted in the storage medium interface 928.The input device 929 includes, for example, a touch sensor that detectsa touch on the screen of the display device 930, a button, a switch, orthe like and receives an operation of a user or an input of information.The display device 930 includes a screen of an LCD, an OLED display, orthe like and displays an image of a navigation function or content to bereproduced. The speaker 931 outputs sound of the navigation function orthe content to be reproduced.

The wireless communication interface 933 supports one or more wirelessLAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad andexecutes wireless communication. The wireless communication interface933 may communicate with another apparatus via a wireless LAN accesspoint in an infrastructure mode. Further, the wireless communicationinterface 933 may directly communicate with another apparatus in adirect communication mode such as an ad hoc mode or Wi-Fi Direct.Typically, the wireless communication interface 933 may include abaseband processor, an RF circuit, a power amplifier, and the like. Thewireless communication interface 933 may be a memory that stores acommunication control program, a processor that executes the program, ora one-chip module that integrates related circuits. The wirelesscommunication interface 933 may support, in addition to the wireless LANsystem, other types of wireless communication systems such as a nearfield wireless communication system, a close proximity wirelesscommunication system, or a cellular communication system. The antennaswitch 934 switches a connection destination of the antenna 935 betweena plurality of circuits included in the wireless communication interface933. The antenna 935 includes a single or a plurality of antennaelements and is used for the wireless communication interface 933 totransmit and receive a wireless signal.

It should be noted that the car navigation apparatus 920 is not limitedto the example of FIG. 13 and may include a plurality of antennas. Insuch a case, the antenna switch 934 may be omitted from theconfiguration of the car navigation apparatus 920.

The battery 938 supplies power to each block of the car navigationapparatus 920 shown in FIG. 13 via feed lines partially shown by brokenlines in the figure. Further, the battery 938 accumulates the power fedfrom the vehicle side.

In the car navigation apparatus 920 shown in FIG. 13, the control unit120 described with reference to FIG. 2 may be implemented in thewireless communication interface 933. Further, at least part of thosefunctions may be implemented in the processor 921. For example, when thecar navigation apparatus 920 transmits the block ACK request framedescribed in FIGS. 7 and 8, a data unit that requires a receiptacknowledgement can be suitably selected and a transmission destinationcan be notified of the data unit according to a change in situation ofthe wireless transmission path or the like. Thus, the convenience can beimproved.

Further, the wireless communication interface 933 may operate as theabove-mentioned wireless communication apparatus (AP) 100 and providewireless connection to a terminal carried by the user of the vehicle.

Further, the technology according to the present disclosure may beachieved as an in-vehicle system (or vehicle) 940 including one or moreblocks of the above-mentioned car navigation apparatus 920, thein-vehicle network 941, and a vehicle-side module 942. The vehicle-sidemodule 942 generates vehicle-side data such as a vehicle speed, anengine r.p.m., or failure information and outputs the generated data tothe in-vehicle network 941.

2-3. Third Application Example

FIG. 14 is a block diagram showing an example of a schematicconfiguration of a wireless access point 950 to which the technologyaccording to the present disclosure is applicable. The wireless accesspoint 950 includes a controller 951, a memory 952, an input device 954,a display device 955, a network interface 957, a wireless communicationinterface 963, an antenna switch 964, and an antenna 965.

The controller 951 may be, for example, a CPU or a DSP (Digital SignalProcessor) and operates various functions (e.g., access restriction,routing, encryption, firewall, and log management) of higher-orderlayers than the IP (Internet Protocol) layer of the wireless accesspoint 950. The memory 952 includes a RAM and a ROM and stores programsto be executed by the controller 951 and various types of control data(e.g., terminal list, routing table, encryption key, security setting,and log).

The input device 954 includes, for example, a button or a switch andreceives an operation of a user. The display device 955 includes an LEDlamp or the like and displays an operation status of the wireless accesspoint 950.

The network interface 957 is a wired communication interface for thewireless access point 950 to be connected to a wired communicationnetwork 958. The network interface 957 may include a plurality ofconnection terminals. The wired communication network 958 may be a LANsuch as Ethernet (registered trademark) or may be a WAN (Wide AreaNetwork).

The wireless communication interface 963 supports one or more wirelessLAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, and 11ad andprovides wireless connection to a near terminal to serve as an accesspoint. Typically, the wireless communication interface 963 may include abaseband processor, an RF circuit, a power amplifier, and the like. Thewireless communication interface 963 may be a memory that stores acommunication control program, a processor that executes the program, ora one-chip module that integrates related circuits. The antenna switch964 switches a connection destination of the antenna 965 between aplurality of circuits included in the wireless communication interface963. The antenna 965 includes a single or a plurality of antennaelements and is used for the wireless communication interface 963 totransmit and receive a wireless signal.

In the wireless access point 950 shown in FIG. 14, the control unit 120described with reference to FIG. 2 may be implemented in the wirelesscommunication interface 963. Further, at least part of those functionsmay be implemented in the controller 951. For example, when the wirelessaccess point 950 transmits the block ACK request frame described inFIGS. 7 and 8, a data unit that requires a receipt acknowledgement canbe suitably selected and a transmission destination can be notified ofthe data unit according to a change in situation of the wirelesstransmission path or the like. Thus, the convenience can be improved.

It should be noted that the embodiment described above is an example forembodying the present technology and that matters in the embodiment andmatters specifying the invention in the Claims have respectivecorrespondence relationships. In a similar manner, the mattersspecifying the invention in the Claims and matters in the embodiments ofthe present technology, which are denoted by the same names as thematters specifying the invention, have respective correspondencerelationships. However, the present technology is not limited to theembodiment and can be embodied by variously modifying the embodimentwithout departing from the gist of the present technology.

Further, the processing procedures described in the above embodiment maybe understood as a method including a series of those procedures.Alternatively, the processing procedures described in the aboveembodiment may be understood as a program for causing a computer toexecute the series of procedures or as a recording medium storing thatprogram. As the recording medium, for example, a CD (Compact Disc), anMD (Mini Disc), a DVD (Digital Versatile Disc), a memory card, a Blu-ray(registered trademark) Disc, and the like may be used.

It should be noted that the effects described in this specification aremerely illustrative and are not restrictive, and additional effects maybe provided.

It should be noted that the present technology can also have thefollowing configurations.

(1) A wireless communication apparatus, including

a control unit that controls transmission of a receipt acknowledgementrequest including information, the information specifying a data unitthat requires a receipt acknowledgement response in a plurality oftransmitted data units.

(2) The wireless communication apparatus according to (1), in which

the control unit generates the information according to a priority ofeach of the plurality of transmitted data units.

(3) The wireless communication apparatus according to (2), in which

the control unit generates the information on a basis of a referencepriority, the reference priority being a reference regarding necessityof the receipt acknowledgement response.

(4) The wireless communication apparatus according to (3), in which

the control unit changes the reference priority according to a situationof a wireless transmission path.

(5) The wireless communication apparatus according to (4), in which

the control unit changes the reference priority according to an errorrate of the wireless transmission path.

(6) The wireless communication apparatus according to (5), in which

the control unit changes the reference priority when the error rate ofthe wireless transmission path rises.

(7) The wireless communication apparatus according to (4), in which

the control unit changes the reference priority according to acongestion degree of the wireless transmission path.

(8) The wireless communication apparatus according to (7), in which

the control unit changes the reference priority when the wirelesstransmission path is congested.

(9) The wireless communication apparatus according to (3), in which

the control unit changes the reference priority according to a state ofa transmission buffer that holds a data unit to be transmitted.

(10) The wireless communication apparatus according to (9), in which

the control unit changes the reference priority when data units held inthe transmission buffer reach a predetermined amount.

(11) The wireless communication apparatus according to (1), in which

the control unit generates the information according to a situation of awireless transmission path.

(12) The wireless communication apparatus according to (11), in which

the control unit generates, when the wireless transmission path iscongested, the information in which the number of data units thatrequire the receipt acknowledgement responses is changed.

(13) The wireless communication apparatus according to (1), in which

the control unit generates the information according to a state of atransmission buffer that holds data units to be transmitted.

(14) The wireless communication apparatus according to (13), in which

the control unit generates, when the data units held in the transmissionbuffer reach a predetermined amount, the information in which the numberof data units that require the receipt acknowledgement responses ischanged.

(15) The wireless communication apparatus according to any one of (1) to(14), in which

the control unit sets the data unit whose timing of output to anapplication in a wireless communication apparatus being a transmissiondestination of the plurality of data units has come as a data unit thatdoes not require the receipt acknowledgement response, and generates theinformation.

(16) The wireless communication apparatus according to (15), in which

the control unit determines that the timing has come by measuring anelapsed time after transmission of the plurality of data units.

(17) The wireless communication apparatus according to any one of (1) to(16), in which

the control unit specifies the data unit, the data unit being the lasttransmitted data unit in the data units that are consecutivelytransmitted and do not require the receipt acknowledgement responses, asa data unit that does not require the receipt acknowledgement response.

(18) The wireless communication apparatus according to (17), in which

the control unit specifies a data unit that requires the receiptacknowledgement response by using sequence numbers provided to theplurality of transmitted data units.

(19) A wireless communication apparatus, including:

a reception unit that receives a plurality of data units and a receiptacknowledgement request including information, the informationspecifying a data unit that requires a receipt acknowledgement responsein the plurality of data units; and

a control unit that controls, upon reception of a data unit other thanthe data unit that requires the receipt acknowledgement response basedon the received receipt acknowledgement request, output of the data unitto an application.

(20) The wireless communication apparatus according to (19), in which

the control unit further controls transmission of a receiptacknowledgement for only the data unit in the plurality of received dataunits that requires the receipt acknowledgement response based on thereceived receipt acknowledgement request.

REFERENCE SIGNS LIST

-   10 wireless communication system-   21 Internet connection unit-   22 information input unit-   23 device control unit-   24 information output unit-   100, 200, 210, 220 wireless communication apparatus-   101 interface unit-   102 transmission buffer-   103 sequence management unit-   104 reception buffer-   105 transmission frame creation unit-   106 wireless signal transmission processing unit-   107 reception frame extraction unit-   108 wireless signal reception processing unit-   109 antenna control unit-   111, 112 antenna element-   120 control unit-   121 block ACK request sequence setting unit-   122 block ACK request sequence determination unit-   123 block ACK transmission unit-   124 block ACK reception unit-   125 traffic determination unit-   126 access control unit-   190, 290 application-   900 smartphone-   901, 921 processor-   913, 933, 963 wireless communication interface-   919 auxiliary controller-   920 car navigation apparatus-   950 wireless access point-   951 controller

The invention claimed is:
 1. A wireless communication apparatus,comprising circuitry configured to control reception of a receiptacknowledgement request including information, the informationspecifying a data unit that requires a receipt acknowledgement responsein a plurality of received data units, wherein the information specifiesto set the data unit whose timing of output to an application in thewireless communication apparatus has come as a data unit that does notrequire the receipt acknowledgement response, wherein the information isaccording to a state of a transmission buffer in a transmission sourcethat holds data units to be transmitted, and wherein, when the dataunits held in the transmission buffer reach a predetermined amount, theinformation specifies that the number of data units that require thereceipt acknowledgement responses is changed.
 2. The wirelesscommunication apparatus according to claim 1, wherein the information isaccording to a priority of each of the plurality of received data units.3. The wireless communication apparatus according to claim 2, whereinthe information is on a basis of a reference priority, the referencepriority being a reference regarding necessity of the receiptacknowledgement response.
 4. The wireless communication apparatusaccording to claim 1, wherein, when a wireless transmission path iscongested, the information specifies that the number of data units thatrequire the receipt acknowledgement responses is changed.
 5. A wirelesscommunication apparatus, comprising circuitry configured to controlreception of a receipt acknowledgement request including information,the information specifying a data unit that requires a receiptacknowledgement response in a plurality of received data units, whereinthe information specifies the data unit, the data unit being the lastreceived data unit in data units that are consecutively received and donot require the receipt acknowledgement responses, as a data unit thatdoes not require the receipt acknowledgement response, wherein theinformation specifies a data unit that requires the receiptacknowledgement response by using sequence numbers provided to theplurality of received data units.
 6. A wireless communication method,comprising: controlling, using circuitry, reception of a receiptacknowledgement request including information, the informationspecifying a data unit that requires a receipt acknowledgement responsein a plurality of received data units, wherein the information specifiesto set the data unit whose timing of output to an application in thewireless communication apparatus has come as a data unit that does notrequire the receipt acknowledgement response, wherein the information isaccording to a state of a transmission buffer in a transmission sourcethat holds data units to be transmitted, and wherein, when the dataunits held in the transmission buffer reach a predetermined amount theinformation specifies that the number of data units that require thereceipt acknowledgement responses is changed.
 7. A wirelesscommunication method, comprising: controlling, using circuitry,reception of a receipt acknowledgement request including information,the information specifying a data unit that requires a receiptacknowledgement response in a plurality of received data units, whereinthe information specifies the data unit, the data unit being the lastreceived data unit in data units that are consecutively received and donot require the receipt acknowledgement responses, as a data unit thatdoes not require the receipt acknowledgement response, and wherein theinformation specifies a data unit that requires the receiptacknowledgement response by using sequence numbers provided to theplurality of received data units.